/*
 * @(#)ShellCD.java	1.0 Apr 18, 2008
 *
 *	The MIT License
 *
 *	Copyright (c) 2008 Malachi de AElfweald <malachid@gmail.com>
 *
 *	Permission is hereby granted, free of charge, to any person obtaining a copy
 *	of this software and associated documentation files (the "Software"), to deal
 *	in the Software without restriction, including without limitation the rights
 *	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the Software is
 *	furnished to do so, subject to the following conditions:
 *
 *	The above copyright notice and this permission notice shall be included in
 *	all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *	THE SOFTWARE.
 */
package org.eoti.io.console.shell.cmd;

import org.eoti.io.console.Terminal;
import org.eoti.io.console.shell.ShellException;
import org.eoti.io.console.shell.ShellFileExtension;

import java.io.File;
import java.util.*;

public class ShellCD extends ShellFileExtension
{
	public ShellCD(){super();}

	public void execute(List<String> arguments)
			throws ShellException
	{
		if(arguments.isEmpty())
		{
			shell.setCurrentPath(shell.getEnv(Terminal.DefinedEnv.DEFAULT_CURDIR));
			return;
		}

		if(arguments.size() > 1)
			error("Incorrect number of arguments. Expecting 'cd' or 'cd <dir>'.");

		String newPath = arguments.get(0);
		File newDir = getFile(newPath);
		if(newDir == null)
			error("Unable to change directory to '%s'.", newPath);

		List<File> roots = Arrays.asList(File.listRoots());
		if(roots.contains(newDir) && (newDir.getFreeSpace() == 0))
			error("'%s' has no media.", newPath);

		if(!newDir.exists() || newDir.lastModified() == 0)
			error("Directory '%s' does not exist.", newPath);

		shell.setCurrentDirectory(newDir);
	}

	public String getName()
	{
		return "cd";
	}

	public String getUsage()
	{
		return "'cd <dir>' to change into a specific directory.\n'cd' to reset it to the default directory.";
	}
}
